Why doesn't every animal own a length?

I mean dogs do, so why not hamsters? Yeah i sound stupid.
Thanks contained by advance x
All female animals come into heat at one time or another. You just consideration it more in dogs and cats.
Will my guinea pigs receive along?
actually every animal has a HEAT or ESTRUS cycle...
dogs do NOT have "periods" similar to people do.. dogs bleed when they are in heat.. when they can take pregnant - this is OPPOSITE to when human females bleed
What can i nurture this dog?
Answers:    the above is almost correct, adjectives female adult mammals will have some form of length.
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